Question

A flea walking along a ruler moves from the 45 cm mark to the 27 cm mark. It does this in 3 seconds. What is the speed? What is the velocity?

(Define increasing numbers to be the positive direction and decreasing numbers to be the negative direction.)

Answer 1

Step-by-step explanation:

In the calculation of distance we do not take into account the direction of movement .So only magnitude of movement is taken care of.

On the other hand , in respect of displacement , we take into account even direction of movement along with magnitude.

Distance covered by flea = 45 - 27 = 18 cm

Displacement by flea = 27 - 45 = - 18 cm

Speed = Distance covered / time

= 18 / 3 = 6 cm / s

Velocity = - 18 / 3 = - 6 cm /s.